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Chironex fleckeri

Chironex fleckeri
3.Oct.2022-Expires: 7 days - Do not archive







Chironex fleckeri


Australian box jellyfishBox jellies
Box jellyBox jellyfish
Chironex box jellyfishIndringa
Sea stingerSea wasp



These tropical jellyfish are mainly found in coastal waters in tropical areas of northern Australia. These animals frequent the shore area adjacent to mangrove creeks in which they breed, and from which they swim to feed in summer (October to May). The closer the geographical location to the equator, the greater the number of months Chironex fleckeri is found.  In Darwin, Chironex fleckeri stings have occurred for every month of the year, except for one month. When fishing for prey they favor calm water close to shore, free of snags over clear sandy bottoms, where they extend and trail their curtain of tentacles behind them.[1]


Intervention Level

Child and Adult

Medical observation, preferably in an advanced care facility with Box Jellyfish Antivenom available is recommended for:
- Any individual stung or suspected to have been stung by a box jellyfish

Observation Period

Observation at Home

All patients require medical attention.

Medical Observation

Asymptomatic patients should be observed for 2 hours. If they remain asymptomatic in this time frame, the patient may be discharged into the care of a reliable observer and given instructions to return should any symptoms develop.
Stings may result in severe envenoming; symptomatic patients must not therefore be discharged until their symptoms have subsided.


Sticky tape or scalpel sampling can be performed to identify the jellyfish in question, sticky tape is applied to skin or the skin is scraped with a scalpel and then transferred to a microscope slide for examination; this allows nematocysts to be identified on the basis of morphology.[2][3]However this currently is a research tool only. A negative result does not rule out a jellyfish sting.

Admission Criteria

Any patient with symptoms must be admitted to a medical facility with Box Jellyfish Antivenom and advanced life support.



Most stings are minor but all must be treated as potentially lethal.
In all cases retrieve and restrain the victim on the beach, prevent rubbing of attached tentacles and vigorous muscular activity. Commence and sustain cardiopulmonary resuscitation (CPR) if indicated, this always takes absolute priority.
Flush the affected area liberally with vinegar for at least 30 seconds, and only then carefully remove any adherent tentacles.[4] If the effects are minor, pain may be managed with local application of ice,[5][6] simple analgesia, and oral antihistamines; there should be early medical inspection in case of local skin damage. If pain does not respond, parenteral opioid analgesia may be required, or administration of Box Jellyfish  Antivenom which appears effective for pain relief if administered early. Antivenom is also indicated in severe envenomings to reduce life-threatening complications, and possibly reduce scarring.[7]
Cardiac dysrhythmia and arrest are particular concerns, and possibly may develop within minutes of the stinging contact. Pulmonary edema and respiratory depression/failure may subsequently evolve. Multiple vials of antivenom should be administered for these indications, but its efficacy in the management of cardiorespiratory dysfunction remains uncertain,[7] and advanced supportive care, including mechanical ventilation, is likely required to maintain such patients.
Dermonecrosis is a frequent complication of serious stings, and box jellyfish antivenom has been reported to improve both acute and long-term cutaneous damage.[8] Acute skin markings often resolve spontaneously. Thus acute dermonecrosis should be treated as a burn with specific attention to avoiding secondary bacterial infection. Delayed hypersensitivity reactions are a common late complication of stings occurring some 7 to 14 days after the event.[9] Serum sickness is a potential concern in those receiving antivenom, particularly multiple doses.
Emergency Stabilization
Enhanced Elimination
Supportive Care


Ensure Adequate Cardiopulmonary Function


Ensure the airway is protected if compromised (intubation may be necessary).
Immediately establish secure intravenous access.

Cardiac Arrest

Cardiac dysrhythmia or arrest may occur within minutes of a sting – particularly in children. Commence and sustain cardiopulmonary resuscitation (CPR) if indicated, this takes priority over application of vinegar to neutralize tentacle stinging apparatus.
Prolonged cardiac resuscitation following standard protocols may be appropriate in selected cases as recovery with a good neurological outcome is reported in some severely poisoned patients receiving CPR for hours.[10] Artificial circulatory support interventions including veno-arterial or veno-venous extracorporeal membrane oxygenation (VA- or VV-ECMO), where available, can be considered for selected cases of severe refractory shock or severe respiratory failure due to acute respiratory distress syndrome.[10][11] There is growing experience treating poisoned patients at many ECMO-capable centers.[12][13]
Cardiopulmonary resuscitation should therefore be prolonged, and ideally not abandoned until at least 6 vials of intravenous box jellyfish antivenom have been administered.[14]


Hypotension in children is determined by age and systolic blood pressure
Hypotension if Systolic Blood Pressure (mm Hg) is:
0 to 28 days
< 60
1 to 12 months
< 70
1 to 10 years
< 70 + (age in years x 2)
> 10 years
< 90
Administer an isotonic crystalloid fluid
10 mL/kg IV over 5 to 10 minutes
If the systolic blood pressure does not return to the normal range, give a further 10 mL/kg body weight of the isotonic crystalloid over 5 to 10 minutes.
The intraosseous route can be used if IV access is difficult or delayed.
Administer a bolus of isotonic crystalloid fluid if systolic blood pressure is less than 100 mmHg.
Isotonic crystalloid fluid dose:
20 mL/kg IV over 5 to 10 minutes
If the systolic blood pressure does not return to the normal range, give a further 10 mL/kg body weight normal saline over 5 to 10 minutes.
The intraosseous route can be used if IV access is difficult or delayed.

Flush with Vinegar

Retrieve and restrain the victim on the beach and prevent tentacle rubbing and vigorous muscular activity. Immediately douse the sting area liberally with vinegar for a minimum of 30 seconds;[15] do not attempt to remove adherent tentacles before this step, unless no vinegar is available, in which case carefully pick off the tentacles.

Pressure Bandage with Immobilization First Aid

Pressure bandage with immobilization first aid was proposed to be beneficial because of its effectiveness in treating elapid snake and funnel web spider bites,[16][17] however, there is no evidence to support the use of pressure bandage with immobilization in the management of jellyfish stings.[18][19] Evidence suggests it may actually increase the amount of venom that is injected into the victim.[20]

Emergency Monitoring

If there are signs of systemic envenoming:

Heart rate/rhythm
Pulmonary function
Level of consciousness



Flush the affected area with vinegar (3 to 10 % acetic acid in water) as soon as possible,[21][22] and continue to irrigate for 30 seconds. After flushing, carefully remove any adherent tentacles.[4]
Vinegar may irritate the sting sites, but should still be applied.[23] It is not designed to relieve pain associated with jellyfish stings, but to prevent further discharge of nematocysts. Nematocyst inhibition and analgesia are two distinct and separate areas of management.
The fresh sting area should never be rubbed with sand, towels or anything else. Methylated spirits is not recommended.[4]


Remove contact lenses. Irrigate immediately with water or saline for at least 30 minutes. If the eye is contaminated with solid particles, the eyelid should be completely everted and any solid material removed as quickly as possible while continuing to irrigate the eye. A topical anesthetic is recommended to enable the patient to open their eyelids sufficiently for effective irrigation.
The eye should be examined immediately following flushing with a slit-lamp microscope and fluorescein stain. Any evidence of injury requires specialist ophthalmological assessment.


Box Jellyfish Antivenom

There have been conflicting studies over the efficacy of box jellyfish antivenom, its efficacy remains to be proven, particularly in relation to preventing fatalities. This is because of the dramatic nature of the sting, with death or survival usually determined within minutes.[14] Studies in animals have shown that the antivenom is largely ineffective in preventing cardiovascular collapse even when administered before envenoming;[24] this lack of effect may be due to the antivenom being unable to bind venom in sufficient time to prevent the venoms rapid effects.[24][25]
Whether the antivenom has the potential to reverse life-threatening cardiotoxicity in humans remains uncertain; the antivenom would need to be given early and in large doses (up to 6 vials) in such a scenario.[26][14] Should more than 6 vials be required contact an experienced medical toxicologist for advice. The antivenom may be beneficial if given early in the relief of severe skin pain.[8][27]


Box Jellyfish Antivenom should be administered to any patient if:
- Cardiorespiratory dysfunction/arrest is apparent
- Severe pain is unresponsive to other managements
Other suggested, but not uniformly accepted, indications include:
- The total sting area is greater than the area equivalent to one half of one limb (especially in children)
- Cosmetic damage such as to the face is likely (the possible benefit must be carefully considered given the risks of antivenom administration)
However, these indications should be discussed with a medical toxicologist.

Dose and Administration

Only administer if clearly indicated. Note the dose for a child is the same as that for an adult.
Pre-medication is not recommended although controversy exists.[28][29][30]
Prior to use of jellyfish antivenom, ensure adequate resuscitation equipment is available for the management of anaphylaxis, and that an appropriate dose of epinephrine (adrenaline) is drawn up as outlined in management of anaphylaxis. Note that anaphylaxis has not yet occurred with this antivenom and the need for early administration in severe cases may outweigh the need to be fully prepared to treat anaphylaxis.
Initial Box Jellyfish Antivenom dose
Life threatening cardiac or respiratory failure:
1 to 3 vials IV (if cardiac arrest, consider 6 vials undiluted as rapid IV push)
Systemic envenoming (collapse, hypotension, significant cardiac dysrhythmia):
1 vial IV
Refractory pain:
1 vial IV
Preferably dilute antivenom up to 1 in 10 in an isotonic solution (e.g. normal [0.9%] saline); dilution should be less for children due to fluid load. Administer intravenously via a drip-set, commence very slowly and increase rate if there is no adverse reaction. Total dose should be given over 15 to 30 minutes.
Patients must be closely monitored for anaphylaxis during and for 30 minutes after the infusion.
Further Box Jellyfish Antivenom doses
Should cardiovascular compromise not be reversed with the initial dose, it is recommend that advice from a medical toxicologist (at the bedside or through a Poison Center) is obtained regarding whether further antivenom therapy is required.


There is no absolute contra-indication to this potentially life-saving intervention.
Those at increased risk of severe reaction include patients with history of:
Previous reaction to antiserum

Adverse Effects

The antivenom being a foreign protein could cause sensitization and, therefore, should not be given for insignificant lesions or wheals.[17]
Closely monitor the patient for indications of anaphylaxis including:
Airways obstruction
Serum Sickness
Serum sickness may occur some 4 to 14 days following antivenom administration.

Patients should be made aware of the signs and symptoms of serum sickness including:
Joint aches
If high doses of antivenom have been administered prophylaxis with an oral steroid such as prednisolone may be considered, and follow-up arranged. Commence prophylaxis on day 2 to 3 post envenoming.
Prednisolone dose
1 mg/kg (up to 50 mg) per day orally for 5 days
50 mg per day orally for 5 days


The Box jellyfish is one of the most dangerous venomous creatures in the world, however, most typical stings rarely require hospitalization.[14][9][6]
Following exposure, the victim may experience immediate excruciating pain which increases in mounting waves, despite removal of the tentacle. The victim may scream and become irrational.[32][33] Areas of contact appear as purple or brown lines often compared to the marks made by a whip.[32] A pattern of transverse bars is usually visible and whealing is prompt and massive. Edema, erythema, and vesiculation soon follow and when these subside patches of full thickness necrosis are revealed.[32]
Patients may develop a variety of systemic effects that include acute pulmonary edema, cardiovascular instability and dysrhythmias, hypertension, hypotension, shock, and cardiac arrest. When death occurs it is usually due to a (presumed) cardiac arrest on the beach.

Routes of Exposure

Clinical effects may develop following contact with intact or dismembered jellyfish, or nets containing body parts. Exposures generally occur when people are swimming in the sea or when specimens are washed up on the beach and handled or stood on. Jellyfish do not “attack” humans and stings are usually the result of a creature drifting into humans or humans colliding into a jellyfish.

Onset/Duration of Symptoms

Local effects are generally noted immediately. Victims experience intense excruciating localized skin pain, peaking at 15 minutes and waning over the subsequent 24 hours; edema, erythema and vesiculation occur initially and when these subside (after some 10 days) patches of full thickness necrosis are revealed. Death, if it occurs, is usually within 20 minutes of the sting.[14]

Severity of Envenoming

Severity is dependent upon area of discharging tentacle contact. Involvement of greater than 10% skin area is potentially lethal, especially in children.[7] Death follows cardiopulmonary failure.
Mild Box Jellyfish EnvenomingModerate Box Jellyfish EnvenomingSevere Box Jellyfish Envenoming
Local pain
Cutaneous linear marks of sting
Severe local or generalized pain
Acute respiratory distress
Acute pulmonary edema
Respiratory failure
Cardiac arrest


Delayed hypersensitivity reactions may occur in patients following stings. The reaction consists of a pruritic erythematous maculopapular rash that appears at the initial tentacle contact points and occurs 7 to 14 days after envenoming. The reaction may spontaneously resolve; most recover following treatment with oral antihistamines and topical corticosteroids.[9]


[1] Williamson J, Burnett J. Clinical toxicology of marine coelenterate injuries. In: Meier J, White J, editors. Handbook of clinical toxicology of animal venoms and poisons. Boca Raton (FL): CRC Press; 1995. p. 89-115.
[2] Currie BJ, Wood YK. Identification of Chironex fleckeri envenomation by nematocyst recovery from skin. Med J Aust 1995 May 1; 162 (9): 478-80.
[3] Huynh TT, Seymour J, Pereira P, Mulcahy R, Cullen P, Carrette T, Little M. Severity of Irukandji syndrome and nematocyst identification from skin scrapings. Med J Aust 2003 Jan 6; 178 (1): 38-41.
[4] Hartwick R, Callanan V, Williamson J. Disarming the box-jellyfish: nematocyst inhibition in Chironex fleckeri. Med J Aust 1980 Jan 12; 1 (1): 15-20.
[5] Isbister GK, Palmer DJ, Weir RL, Currie BJ. Hot water immersion v icepacks for treating the pain of Chironex fleckeri stings: a randomised controlled trial. Med J Aust 2017 Apr 3; 206 (6): 258-261.
[6] Fenner PJ, Harrison SL. Irukandji and Chironex fleckeri jellyfish envenomation in tropical Australia. Wilderness Environ Med 2000 Winter; 11 (4): 233-40.
[7] White J. CSL antivenom handbook. Melbourne: CSL Ltd: 2001. p. 59-61.
[8] King GK. Acute analgesia and cosmetic benefits of box-jellyfish antivenom. [Letter] Med J Aust 1991 Mar 4; 154 (5): 365-6.
[9] O'Reilly GM, Isbister GK, Lawrie PM, Treston GT, Currie BJ. Prospective study of jellyfish stings from tropical Australia, including the major box jellyfish Chironex fleckeri. Med J Aust 2001 Dec 3-17; 175 (11-12): 652-5.
[10] Gunja N, Graudins A. Management of cardiac arrest following poisoning. Emerg Med Australas 2011 Feb; 23 (1): 16-22.
[11] de Lange DW, Sikma MA, Meulenbelt J. Extracorporeal membrane oxygenation in the treatment of poisoned patients. Clin Toxicol (Phila) 2013 Jun; 51 (5): 385-93.
[12] Weiner L, Mazzeffi MA, Hines EQ, Gordon D, Herr DL, Kim HK. Clinical utility of venoarterial-extracorporeal membrane oxygenation (VA-ECMO) in patients with drug-induced cardiogenic shock: a retrospective study of the Extracorporeal Life Support Organizations' ECMO case registry. Clin Toxicol (Phila) 2020; 58 (7): 705-10.
[13] Ramanathan K, Tan CS, Rycus P, MacLaren G. Extracorporeal membrane oxygenation for poisoning in adult patients: outcomes and predictors of mortality. Intensive Care Med 2017 Oct; 43 (10): 1538-39.
[14] Currie BJ. Marine antivenoms. J Toxicol Clin Toxicol 2003; 41 (3): 301-8.
[15] Fenner PJ, Williamson JA, Blenkin JA. Successful use of Chironex antivenom by members of the Queensland Ambulance Transport Brigade. Med J Aust 1989 Dec 4-18; 151 (11-12): 708-10.
[16] Sutherland SK, Duncan AW. New first-aid measures for envenomation: with special reference to bites by the Sydney funnel-web spider (Atrax robustus). Med J Aust 1980 Apr 19; 1 (8): 378-9.
[17] Williamson JA, Callanan VI, Unwin ML, Hartwick RF. Box-jellyfish venom and humans. [Letter] Med J Aust 1984 Mar 31; 140 (7): 444-5.
[18] Little M. Is there a role for the use of pressure immobilization bandages in the treatment of jellyfish envenomation in Australia? Emerg Med (Fremantle) 2002 Jun; 14 (2): 171-4.
[19] Seymour J, Carrette T, Cullen P, Little M, Mulcahy RF, Pereira PL. The use of pressure immobilization bandages in the first aid management of cubozoan envenomings. Toxicon 2002 Oct; 40 (10): 1503-5.
[20] Pereira PL, Carrette T, Cullen P, Mulcahy RF, Little M, Seymour J. Pressure immobilisation bandages in first-aid treatment of jellyfish envenomation: current recommendations reconsidered. Med J Aust 2000 Dec 4-18; 173 (11-12): 650-2.
[21] Fenner PJ, Williamson JA, Burnett JW, Rifkin J. First aid treatment of jellyfish stings in Australia. Response to a newly differentiated species. Med J Aust 1993 Apr 5; 158 (7): 498-501.
[22] Currie B, Ho S, Alderslade P. Box-jellyfish, Coca-Cola and old wine. [Letter] Med J Aust 1993 Jun 21; 158 (12): 868.
[23] Beadnell CE, Rider TA, Williamson JA, Fenner PJ. Management of a major box jellyfish (Chironex fleckeri) sting. Lessons from the first minutes and hours. Med J Aust 1992 May 4; 156 (9): 655-8.
[24] Winter KL, Isbister GK, Jacoby T, Seymour JE, Hodgson WC. An in vivo comparison of the efficacy of CSL box jellyfish antivenom with antibodies raised against nematocyst-derived Chironex fleckeri venom. Toxicol Lett 2009 Jun 1; 187 (2): 94-8.
[25] Isbister GK. Antivenom efficacy or effectiveness: the Australian experience. Toxicology 2010 Feb 9; 268 (3): 148-54.
[26] Currie B. Clinical implications of research on the box-jellyfish Chironex fleckeri. Toxicon 1994 Nov; 32 (11): 1305-13.
[27] Boyd W. Sea-wasp antivenom in a toddler. [Letter] Med J Aust 1984 Apr 14; 140 (8): 504.
[28] Sutherland SK. Premedication before antivenom therapy. [Letter] Med J Aust 1991 Nov 18; 155 (10): 722.
[29] Sutherland SK. Antivenom use in Australia. Premedication, adverse reactions and the use of venom detection kits. Med J Aust 1992 Dec 7-21; 157 (11-12): 734-9.
[30] Fatovich DM, Turner VF, Hirsch RL. Premedication before antivenom therapy. [Letter] Med J Aust 1992 Apr 6; 156 (7): 510.
[31] White J. A clinician's guide to Australian venomous bites and stings. Melbourne: CSL Ltd: 2013. p. 245-63.
[32] BARNES JH. Observations on jellyfish stingings in North Queensland. Med J Aust 1960 Dec 24; 47(2) (): 993-9.
[33] Maguire EJ. Chironex fleckeri ("sea wasp") sting. Med J Aust 1968 Dec 21; 2 (25): 1137-8.

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